Industrial truck attachment



y 18, 1954 E. R. BACKOFEN ET AL 2,678,743

INDUSTRIAL TRUCK ATTACHMENT Filed Dec. 5, 1951 4 Sheets-Sheet l IN VEN TORS. E. RYAN BACKOF EN WESLEY ZORN May 18, 1954 E. R. BACKOFEN ETAL 2,678,743

INDUSTRIAL TRUCK ATTACHMENT 4 Sheets-Sheet 2 Filed Dec. 5, 1951 IN VEN TORS. E. RYAN BACKOFEN WE S LEY ZORN BY ATTYS May 18, 1954 E. R. BACKOFEN ET AL 2,678,743

INDUSTRIAL TRUCK ATTACHMENT 4 Sheets-Sheet 3 Filed Dec. 5, 1951 INVENTORS E RYAN BACKOFEN BY WESLEY ZORN M ATTYS.

i: in I" May 18, 1954 E. R. BACKOFEN ET AL INDUSTRIAL TRUCK ATTACHMENT 4 Sheets-$heet 4 Filed Dec. 5, 1951 FIG. 5

Patented May 18, 1954 UNITED STATES ATENT OFFICE INDUSTRIAL TRUCK ATTACHMENT E. Ryan Backofen, B

poration of Michigan Application December 5, 1951, Serial No. 260,018

3 Claims. 1

Our present invention relates generally to a load elevating mechanism, and, more particularly, is directed to a lift dump attachment particularly adapted for emptying a dump-bottom type hopper.

A dump-bottom type hopper of the character to which we refer, comprises a substantially rectangular body portion pivotally mounted at its rear end, about a horizontal axis, to a platform portion. The platform portion is supported at its rear end on a pair of spaced legs, and at its forward end is supported on a transversely extending I-beam. A suitable bracket member is secured to the body portion of the hopper, adjacent the rear end thereof. When the hopper is in a normal position, that is, with the platform portion horizontal and the sides of the body portion vertical, a container is defined for storing articles, such as metal castings and the like.

Our present invention is concerned with an attachment for an industrial truck, which is adapted to engage the bracket member of the hopper for raising the latter whereby the forward end of the body portion of the hopper is swung upwardly and away from the forward end of the platform portion. With the hopper in the position last described, the platform portion defines an inclined chute, the lower end of which may be directed to another container or pile for conveying articles from the hopper to the said container or pile.

It is a primary object of our present invention to provide a lift dump attachment, as described, having a minimum overall height.

It has been determined that a considerable force is required to initially break open the hopper. For this reason, it has been found preferable to provide a lift dump attachment having a l to 1 lift wherein the load or hopper engaging means is moved upwardly conjointly with the piston rod of the elevating hydraulic assembly. This 1-1 lift, however, if continuous through the entire range of travel of the load engaging means, would require the attachment to be of considerable height.

It is a primary feature of our present invention that the load engaging means initially moves upwardly at the same rate of speed as the piston rod of the elevating hydraulic assembly, and after the load engaging means has been raised a predetermined distance, the latter moves upwardly twice as fast as the piston rod of the elevating hydraulic assembly.

After the hopper has been initially broken open, the force required to move the hopper to a full open position is less than the initial opening force required. Thus, a 2-1 lift provides suflicient force to complete the opening of the hopper after the latter has been initially broken open. By providing a sequentially operable 1-1 and 2-1 lift, the overall vertical height of the attachment may be maintained at a minimum without sacrifice of operating efficiency.

The lift dum attachment of our present invention, which has a sequentially operable 1-1 and 2-1 lift, comprises first frame means which is adapted to be secured to the load supporting carriage of an industrial truck. Slidably mounted in the first frame means is second frame means. A hydraulic assembly is provided for effecting vertical movement of the second frame means. A carriage assembly is mounted for movement within the second frame means and suitable stop means is provided for engaging the carriage assembly during initial upward movement of the second frame means for causing the carriage assembly to move upwardly conjointly with the second frame means. In addition, sprockets are rotatably mounted to the second frame means and chains are trained over the sprockets. The chains are secured at their one ends to the carriage assembly, and at their other ends to means slidably mounted along the actuating cylinder, which means in the embodiment of our invention to be disclosed hereinafter comprises a collar member. In the specific form of our invention to be disclosed, the collar member is adapted to engage the upper cap of the cylinder of the elevating hydraulic assembly after the second frame means has been raised a predetermined height for providing a reaction point, whereby upon continued upward movement of the second frame means, the chains will cause the carriage assembly to move upwardly at twice the speed that the second frame means moves.

Now, in order to acquaint those skilled in the art with the manner of constructing and using devices in accordance with the principles of our present invention, we shall describe in connection with the accompanying drawings, a preferred embodiment of our present invention.

In the drawings:

Figure 1 is a perspective view of an industrial truck to which is secured, at the forward end thereof, the lift dump attachment of our present invention;

Figure 2 is a front elevational view of the lift dump attachment of Figure 1;

Figure 3 is a plan view of the lift dump attache ment of Figure 2:

Figure 4 is a side elevational view of the lift dump attachment of Figure 2; and

Figure 5 is a perspective view of the industrial truck of Figure 1 with the lift dump attachment in an elevated position.

Referring now to Figure 1, there is shown an industrial truck, indicated generally by the reference numeral Ill, having a pair of drive wheels disposed at the forward end thereof, and a pair of steering wheels I2 disposed at the rear end thereof. The truck l is provided with a conventional prime mover and drive means for effecting driving of the forward wheels Mounted on the truck 0 is an operators seat l3, and disposed forwardly thereof is a hand steering wheel |4 mounted on a steering column l5 which is operatively connected in a conventional manner to the rear steering wheels I2. Pivotally mounted at the forward end of the truck I0 is a conventional generally vertically extending mast, indicated generally by the reference numeral l6, which comprises a pair of opposed facing, vertically extending, outer channel members IT, in which are slidably mounted a pair of vertically extending opposed facing channel members H3. The outer channel members ll, adjacent their upper ends, are maintained in spaced relation by means of a brace l9. The inner slidable channel members I8, adjacent their upper ends, are interconnected by means of a cross head 20, which has suitable connection to the upper end of the piston rod 2| of a hydraulic piston and cylinder assembly, indicated generally by the reference numeral 22. The assembly 22 is secured, at its lower end, to the outer channel members |l. Rotatably mounted on the cross head 20, about a horizontal axis, are a pair of sprocket gears '23 over which a pair of chains 24 are trained. The chains 24, adjacent their one ends, have connection to a brace member, not shown, secured to the outer fixed channel members intermediate of the ends thereof. The chains 24, adjacent their other ends, are suitably connected to a load supporting carriage which is mounted for upward and downward movement within the inner channel members i8. Detachably secured to the forward surface of the load supporting carriage are a pair of vertically spaced, transversely extending, frame members or fork bars 25 and 26.

Movement of the load supporting carriage within the inner channel members I8 is effected by selectively admittin fluid under pressure to the lower end of the cylinder of the hydraulic piston and cylinder assembly 22. In this instance, the flow of fluid under pressure to the lower end of the cylinder causes the piston rod 2| to be urged upwardly, which, in turn, causes upward movement of the inner channel members l8, cross head 20, and sprocket gears 23. As the sprocket gears 23 are moved upwardly the chains 24, which as aforedescribed, are fixed at their one ends, rotate about the sprocket gears 23 thus urging the load supporting carriage upwardly. When it is desired to lower the load supporting carriage, fluid under pressure is bled from the lower end of the cylinder of the assembly 22 thus permitting the piston rod 2| to move downwardly under the weight of gravity.

Brackets 21 are secured to the outer sides of the outer channel members ll, intermediate of the ends thereof, and pivotally mounted to the brackets 21 are hydraulic piston and cylinder assemblies indicated generally at '28 which are carried by the truck l0. By the selective admis- 4 sion of fluid under pressure to either the forward or rear ends of the hydraulic piston and cylinder assemblies 28, the mast assembly, indicated generally at l6, may be tilted either forwardly or rearwardly.

Secured to the forward surfaces of the fork bars 25 and 26, in a manner to be described fully hereinafter, is the lift dump attachment of our present invention. The attachment is particularly adapted for use with a skid box or hopper of the character indicated generally at 3|. The hopper 3| is of the dump bottom type and comprises a substantially rectangular body portion 32 pivotally mounted at its rear end, about a horizontal axis, to a platform portion 33. The platform 33 is formed with upturned sides 34 and is supported at its rear end on a pair of legs 35. A transverse I-beam 36 is secured to the underside of the platform 33 adjacent the forward end thereof. A suitable bracket 37 is secured to the rear end of the body portion 32.

The hopper 3| is normally in the position shown in Figure 1, in which position a container is defined for storing articles such as metal castings and the like. After the hopper 3| has been filled with castings, or the like, and it is desired to empty the hopper 3|, the device of our present invention is adapted to effect raising of the rear end of the body portion 32 relative to the platform 33. As shown in Figure 5, the platform 33 together with the upturned sides 34, define an inclincd chute, the lower end of which may be directed toward another container or pile for conveying articles from the hopper 3| to the said container or pile.

The construction of the lift dump attachment of our present invention shall now be described in detail.

A pair of spaced vertically extending channel members 4| and 42, C-shaped in cross section, are secured at their lower ends to the forward surfaces of the fork bars 25 and 26. The channel members 4| and 42 are maintained in proper spaced relation, at their upper ends, by means of a horizontal channel brace member 43. The channel members 4|, 42 and 43 define a first frame means. slidably mounted in the channel members 4| and 42, respectively, are channel members 44 and 45. The inner slidable channel members 44 and 45 are interconnected at their upper ends by a pair of spaced apart transversely extending brace members 46 and 47. The braces 46 and 4'! are maintained in position by spacers 48 and 49. The channel members 44 and 45, :brace members 46 and 41, and spacers 48 and 49, define a second frame means which is slidably mounted in the a-foredescribed first frame means.

Vertical movement of the inner slidable channel members 44 and 45, together with the transvverse brace members 46 and 41, is effected by means of power actuated means which preferably comprises a centrally located hydraulic piston and cylinder assembly indicated generally by the reference numeral 50. The hydraulic assembly 50 comprises a cylinder 5| which is secured, at its lower end, by bolts 52 to a plate 53 suitably secured, as by Welding, to the front face of the lower fork bar 26. The cylinder support plate 53 is reinforced by a substantially triangular gusset plate 54.

The upper end of the cylinder 5| is provided with a cylinder cap 55, to which is secured, by bolts 56, a gland clamp plate 5! through which extends a piston rod 58. The upper threaded end of the piston rod 58 is secured, by a nut 59, to a horizontal plate 90 which is secured between the inner channel braces 46 and 41 intermediate of the ends thereof.

The hydraulic piston and cylinder assembly 50 is of the double acting type, and, thus, when fluid is admitted to the lower end of cylinder 5! the piston rod 58 is urged upwardly, thereby moving the inner slide top braces 45 and 41, together with the inner channel members 44 and 45, up-- wardly. When fluid under pressure is admitted to the upper end of the cylinder 5| and fluid is simultaneously bled from the lower end of the cylinder 5I the piston rod 58 is urged downwardly thereby causing the inner channel top brace members 46 and 41, together with the inner channels 44 and 45, to move downwardly within the outer channel members 4| and 42.

Mounted for upward and downward movement within the inner slidable channel members 55 and 55 is a carriage assembly indicated generally by the reference numeral II. The carriage II comprises end plates I2 and I3 which are disposed respectively adjacent the inner channel members 34 and 45. Laterally extending pin members M are fixed in the carriage end plate I2 and project into the inner channel member 54. Rotatably mounted on the outer ends of the pin members 14 are rollers I5 which engage the inner surfaces of the leg portions of the inner channel member A l. Laterally extending pin members 15 are fixed in the carriage end plate I3. The outer ends of the pin members I5 project into the inner channel member and rotatably mounted on the projecting ends of the pin members It are rollers TI which engage the inner surfaces of the leg portions of the inner channel member 45.

Thrust roller blocks I8 and 19 are secured respectively to the carriage end plates 12 and It. The blocks [8 and I9 extend into the inner chan nel members 45 and 45 and provide support for rollers 80 and BI which respectively engage the bight portions of the inner channel members 44 and 45.

Secured to the forward edges of the carriage end plates I2 and I3, respectively, are lift brackets 82 and 83 which extend toward each other. interconnecting the lift brackets 82 and 83 is a transversely extending main carriage plate 85 which is secured to the lift brackets 82 and 85 respectively by bolts 85 and 36.

The junction of the carriage end plate I2 and the lift bracket 82 is reinforced at the upper and lower ends thereof by gusset plates 83. The junction of the carriage end plate I3 and the lift bracket 52 is reinforced at the upper and lower ends thereof by gusset plates 89. Welded to the inner channel members 45 and d5, adjacent the lower ends thereof, are carriage bumper plates at and 9!. The bumper plates 90 and 9f act as stops for limiting downward movement of the carriage II relative to the inner channel members It and 45.

Movement of the carriage II within the inner channel members 44 and 45 is accomplished by chain means which shall now be described in detail. Mounted intermediate of the inner channel braces 46 and ll, on spaced apart shafts 93 and 94, are compound sprockets 95 and 95. Trained over the sprockets 95 and 96, respectively, are compound chains 91 and 98. The chains 9? and 98, at their one ends, are riveted to chain anchor pins 99 and I00. The chain anchor pins 99 and I00 are respectively bolted to blocks IUI and I02 fixed to horizontal plates I03 and I04 which are suitably secured to the rear surface of the main carriage plate 84. The mountings of the plates I03 and I04 to the main carriage plale 84 are reinforced by gusset plates I05 and I06.

The other ends of the chains '91 and 98 are riveted to chain anchor pins H4 and H5 which are suitably bolted to opposite sides of a collar member I I5 slidably mounted on the cylinder SI of the hydraulic assembly 59.

The upper edge of the main carriage plate 84 has secured to its upper edge a pair of spaced block members I25 and I21 which provide a journal support for a transverse shaft I28. Secured to the shaft I28, adjacent the block members I25 and I2l, are a pair of J-shaped hook members I29 and I30.

,A pair of L-shaped horizontally spaced load supporting fork frames I3I and I32 are detachably secured along their vertical legs to the aforedescribed fork bars 25 and 26 immediately inwardly of the outer channel members M and 42.

The operation of the lift dump attachment of our present invention is as follows. When it is desired to dump the contents of a loaded hopper, the industrial truck III is aligned with the hopper andv the load supporting forks I3I and I32 are inserted below the platform 33 between the legs 1-5. The hopper 3| is then raised to an elevated position by selectively admitting fluid under pressure to the lower end of the cylinder of the hydraulic assembly 22 of the truck mast I5. After the hopper 5| has been elevated to the desired height, fluid under pressure is admitted to the cylinder 5| of the hydraulic assembly 55 of the lift dump attachment which causes the inner channel top braces 46 and il to be raised together with the inner channel members 44 and 45. The carriage assembly II of the lift dump attachment is also raised by virtue of the stop members and GI engaging the lower end of the carriage end plates I2 and I3. Through the initial range of movement of the inner slides 54 and 45, there is no relative movement between the carriages II and the piston rod 58 and what we term a 1 to 1 lift is provided.

Now, during initial upward movement of the carriage II, the hook members I29 and I35 engage the bracket 3! of the hopper 3I causing the rear end of the latter to be moved upwardly. During upward movement of the rear end of the body portion 32 of the hopper 3|, the forward end of the body portion 32 pivots upwardly and away from the platform portion 33. It has been determined that a considerable force is required to break open the hopper 3|. For this reason, we have provided a lift dump attachment, as described, wherein the carriage II carrying the lift hooks I29 and I35 moves initially at the same speed as the piston rod 58. This 1 to 1 lift, however, if continued through the entire range of travel of the carriage II, would require the attachment to be of considerable height. To overcome the latter objection, the above described chain and collar means are provided, which cause the carriage II and lift hooks 29 and I35 to move upwardly twice as fast as the piston rod 55, after the latter has been actuated through a predetermined range.

As the piston rod 58 of the hydraulic assembly 50 is urged upwardly, the collar member H5 moves upwardly until the latter engages the underside of the cylinder cap 55. At this point,

agsvsmrs 7 the: collarfmember -l Boast-prevented ffrorm'moving further upwardly iand ia reaction-:01 anchoripoint is provided'izori the: chains :19! rand 8.

'Upon further upward movement of the-piston rod '58, 'the :innercchannel' top braces 46 zand=241 continue upwardly, and since the chains ":912and 98"are anchoredeatrtheiri oneaendsathe: latter will travel over :the sprockets r95 and F 96 rcau'sing the ends of the chains :91 and 98, securedrto the carriage l I, to :move :upwardly relative zto :the inner channels 44 ands t5. Thus,tthrongh Kthe final range "of :upward rmovement of the inner channels it and 45, the :carriage II is caused to move upwardly tWiceas: fast as' the. piston. rod 58 providing WhEtiWE term-a 2 to .1 lift.

From the :aforedescribed mperation of 1 the I lift dump attachment (Of 1011! lpresent invention, :it will be readily apparent to those 'skilled inn-the art that the attachment provides :.for initial high forceor power andz-subsequent; high speed :hook travel. After the hopper (3| has been -initially broken open-the force-required to move theihopper to a full open ,position is less i than theinitial opening force required. Thus, :the 2 to =1 lift provides sufficient force to complete theopening of: the hopper l afteiathexlatter hasz beendnitially broken open. Byaproviding asequenti'allyoperable :1 :to -1 l and 2 ::to ;1 lift, the overall vertical height of the attachment 3 maybe maintainedat a minimum without sacrifice 'of operating eldciency. The point at which the 2 to 1 lift becomes effective may be varied by altering zthe lengths-of the chains Q'kand fiiizwhich are secured to the: collar. member I 18.

After the hopper .-3| has been initially broken open, upward movement-0f the rear :end of the body portion 32 causesthe-forward end of the platform portion =33 "to be drawn toward the industrial truck until the I -beamdzi: engaging the forward ends of the-load:supportingforlcs l3! and I32. At this point, :the -I--beam 36 acts to stop: further movement of: the platform "33-: toward the industrial truck and the hopper 3| will assume =the:p0Siti0n Sl'1oWn :in Figure :5. With the hopper 3| in this position, the contents thereof will slide downwardly from the 'body portion 32 along thetinclined; platform -.-:33 "which acts as :a chute for directing =the goods where desired.

The hopper 3 I :may be "emptied :at any :predetermined height within the' capacity of the mast It ofthe industrial truck It. After the hopper 3;! has been emptied, fluid :under pressure :is selectively admitted to the upper end of the cylinder "51 andfluidis simultaneously-bled from the lower end thereof thereby permitting athe piston rodrEiB to'move downwardly atwhich time the hopper 3i will-return to theposition shown'in Figure '1.

Now, while we have shown and described-what We believe to be apreferredembodiment-of :our present invention, it will be understood that various .=modifications and rearrangements :may be made therein without departing :from 'the spirit and scope of ourinvention.

We .claim:

1. For use withanindustrial truck having .an upwardly and downwardly movable load supporting carriage, thecombination of a load elevating mechanism comprising, a first pair of spaced vertically extending channel members secured to said load supporting carriage, a "second pair of channel members 'slidably mounted in-said first channel members, acrossheadiriterconnecting said second channel m-embers, '-a ht-- draulic assembly having ai'cylinder secured to said carriage and I av piston rod secured l to said crosshead, said cylinder having a capya-carriage *as sembly' mountedforimovementlwithin said second channel members, I stop members "secured to the lower ends of saidsecond channel memberswhich engagesaidnicarriage assembly during initial upward'movement of said second channel members for causing said acarri'age'rassembly to'move upwardly conjointly-withrsaid secondchannel' members, J sprockets rotatably carried by said crosshead, chains trained over said "sprockets :and secured at their one ends to s'aidcarriage, means associated with and carried by the other'ends'of said chains which means is adapted to engage the-cylinder ca'pafter said-second channel members have beenraised apredetermined-heightfor providing a reaction :polnt whereby upon continned upward movement-of said second channel members said chains will -causesaidcarriage assembly to move upwardly at agreater speed than said second channel membersmove.

-2. 'F'or use with an industrial truck having an upwardly-and downwardly movable loadsupporting'carriage,-the combination of a load elevating mechanism comprising, first frame means secured to said load I supporting 1 carriage, second frame means slidably mounted in said first frame means, a hy'clraulic assembly having a 1 cylinder secured to: said carriageand: a piston rod secured to said second'frame-means, said cylinder having-acap, a carriage assembl-y'mounted'formovement within said second ir'ame 'means, stop meinbers secured to the 5 lower end of "said second frame means which engage said carriage assembly during initial upward movment of said secondframe means for causing said carriage assemblyto move upwardly "conjointly *with said second frame means, a collar member slidably mounted on said cylinder, sprockets rotatably carried by said second irame :means, chains trained over said sprockets and-secured attheir one e'nds to said carriage-assembly and at'their other'ends to said collar member, and said collar member being adapted to engage said-cylinder =cap after said second framameans has been raised a predetermined hei'ght for providing a reaction point whereby upon continued upward moveme'nt of said second fram'e means said chains will cause said-carriage assembly to move upwardly at twice the speed that said second frame means moves.

'3. For use Wuhan-industrial truckhaving-an upwardly and downwardly movable loadsupportingcarriage, the combination of-a-load elevating mechanism comprising, a first pair of spaced vertically extending channel members secured to said load supporting marriage, a second pair oi channel t members sli'clably mounted in said first channel members, a crosshead interconnecting said second:channel-members, a hydraulic assen1- Joly-having a cyiinder secured to-said carriage and a :piston 'ro'd secured to said crosshea'd, said cylinder having a cap at the upper endthcre'of, a carriage assembly mounted for movem'ent within said second channel members, stop members secured-to the lower ends of said second channel members which engage said "carriage assembly during initial upward movementof said second channel members for'causingsaid carriage assembly to move upwardly 'conjointly with said secondchannel members, a-coll'ar-member slidably mounted "onsaidcylinder, sprockets rotatably carried -by said cross'head, 'chains trained over said sprockets *and secured at their one ends to said carriage assembly and at their other ends to said collar member, and said collar member being adapted to engage said cylinder cap after said second channel members have been raised a predetermined height for providing a reaction point whereby upon continued upward movement of said second channel members said chains will cause said carriage assembly to move upwardly at twice the speed that said second channel members move.

References Cited in the file of this patent UNITED STATES PATENTS Number 2,220,450 2,335,572 2,357,548 2,445,038 

